The present invention relates to a thin-film liquid crystal display panel, and more particularly, to a thin-film liquid crystal display with liquid crystal cell dimensions greatly reduced thickness is uniform but whose weight and volume. The present invention also relates to a method of manufacturing a thin-film liquid crystal display.
As for image display devices currently in use, there are cathode-ray tubes (CRTs), flat liquid crystal displays (LCDs), flat plasma display panels (PDPs), to name a few. Here, the CRT excels in picture quality and brightness, but is too large and too heavy to apply to the current trend to develop large-screen displays.
On the other hand, a flat display device has an advantage in that its dimensions and weight are small and light, respectively, as compared to the CRT, and, thus, is widely being used in various fields. Liquid crystal has been used prevalently since it has the unique characteristics of easy use and is capable of changing its crystal arrangement according to whether an outer electric field is applied or not.
FIG. 1 is a perspective view of a typical liquid crystal display panel. In a typical manufacturing method, ITO (indium tin oxide) electrodes 13 and 19 are respectively formed on two substrates 11 and 11' and then insulating layers 14 and 14' are formed on the whole surface of the resultant structures. The two structures are joined by sandwiching spacers (not shown) between the insulating layers 14 and 14', with the resultant structure having the substrates on the outside. Next, through a method of liquid crystal injection, liquid crystal layer 15 is formed between the insulating layers, completing the formation of a liquid crystal display panel.
The basic driving principle of a liquid crystal display utilizes the characteristics that a liquid crystal's arrangement changes according to whether an outer voltage is applied or not, and light incident upon this liquid crystal layer is either cut off or transmitted on the application of the voltage. Referring to FIG. 1, if a voltage is applied between the upper and lower electrodes 13 and 19, an electric field is formed on liquid crystal layer 15. The electric field formed on the liquid crystal layer orients the liquid crystal to align in one direction, and light incident on the liquid crystal layer of the display device is either cut off or transmitted according to the alignment of the liquid crystal. Such a driving characteristic of the liquid crystal is influenced by the thickness and uniformity of the liquid crystal layer formed within the liquid crystal display panel.
In a conventional liquid crystal display the cell gap is typically formed by depositing a spacer material onto the lower substrate structure and then connecting the upper substrate structure thereon, resulting in non-uniform cell gaps. Because the diameters of the particles of the spacer material are not equal, it is difficult to form a cell gap of uniform thickness as well as to precisely control the thickness of the cell gap formed by particle sizes of the spacer material. This creates a problem in that the conventional liquid crystal display device has poor optical cut-off and transmission characteristics.